From 911/43 to 911/93

[BoogyOne]

Hello guys,

I have a 75' 911S engine to rebuild. Engine code is 911/43 - version with 165 hp.
As you know, in 74', the 911S had 175 hp with engine code 911/93.

Can somebody explain what to do for those extra 10 hp? I mean what to change on this 911/43 for a 911/93...I searched on the forum, I got some info, but nothing clear exactly what to do, or what to change with what.

As I understood, these 10 extra hp feels in the real world, so if however I'm in the stage of rebuilding, maybe it make sense to do it better.

thanks for helping,
Daniel

[Flat6pac]

The 74 had an early exhaust and no back pressure muffler.
75 had later style exhaust and in the next couple years used heat and more restrictive exhaust to meet exhaust requirements.
Bruce

[Steve@Rennsport]

Install a pair of SSI's and a Dansk dual-in,single-out muffler and that will provide the 10 HP you are missing. Don't forget to re-set the CO, too!!!

Its noticeable.

[BoogyOne]

Thanks guys, yes, SSI, or back dated exhaust is the first step (and most easiest) for having extra hp from 2.7.
Regarding, this two engines, 43 and 93, I thought maybe is something more, and this is the time for updates, if I have what.
All clear now.
I heard stories with 200+ hp from a CIS 2.7, but from my point of view, I don't see the balance between extra hp and investment. Of course, this is only my opinion, so don't get me wrong, I like those projects, but are not for me. But at the end, who knows, future is full of surprises

thanks again for your involvement,
Daniel